I ordered this for my grandaughter who hikes a lot. She had a skeeter 35 oz. and always ran out of water plus her food was always in someone elses backpack. Now she can carry her own food and a jacket and pr. of flip flops to give her feet a rest. At 7 yrs old she had day hiked Mt Leconte twice, up and down Alum[10 mi] and up Alum and out Boulevard[13.2 mi.]We refill on top of mtn. before heading down